An LCD has the advantages of portability, low power consumption, and low radiation, and has been widely used in various portable information products such as notebook computers, personal digital assistants (PDAs), video cameras, for example. A conventional LCD such as a twisted nematic (TN) LCD commonly has a rather limited viewing angle. Thus, a multi-domain vertical alignment (MVA)-type LCD was developed to improve the viewing angle.
Referring to FIG. 18, one such MVA-type LCD is shown. The LCD 100 includes a first substrate assembly (not shown), a second substrate assembly 111 generally facing the first substrate assembly, and a liquid crystal layer (not labeled) positioned between the first substrate assembly and the second substrate assembly 111. The liquid crystal layer includes a plurality of liquid crystal molecules 131.
The first substrate assembly includes a common electrode (not shown), and a plurality of first protrusions 119 arranged in that order from top to bottom. The first protrusions 119 are arranged along a plurality of V-shaped paths. The second substrate assembly 111 includes a plurality of gate lines 122, a plurality of first data lines 123, a plurality of second data lines 124, a plurality of common lines 121, a plurality of first pixel electrodes 127, a plurality of second pixel electrodes 128, and a plurality of second protrusions 129. The second protrusions 129 and the first protrusions 119 are arranged alternately.
Every adjacent first data line 123 and second data line 124, and every two adjacent common lines 121 together define a pixel region 10. The gate lines 122 locate crossing the pixel regions 10, and divide each pixel region 10 into a first sub-pixel region 101 and a second sub-pixel region 102.
In the first sub-pixel region 101, a first TFT 125 connects the first pixel electrode 127 with one of the plurality of first data lines 123. The one of the plurality of first data lines 123 provides a plurality of first gray-scale voltages to the first pixel electrode 127. In the second sub-pixel region 102, a second TFT 126 connects the second pixel electrode 128 with one of the plurality of second data lines 124. The one of the plurality of second data lines 124 provides a plurality of second gray-scale voltages to the second pixel electrode 128.
Referring also to FIG. 19, in the first sub-pixel region 101 in each frame, when a first gray-scale voltage is applied to the first pixel electrode 127, and a common voltage is applied to the common electrode, an electric field is generated therebetween. The liquid crystal molecules 131 in the first sub-pixel region 101 twist according to the electric field. The liquid crystal molecules 131 are guided by the protrusions 119, 129 and thereby become aligned in four different directions. Thus four domains are defined according to the protrusions 119, 129. Similarly, in the second sub-pixel region 102 in the same frame, when a second gray-scale voltage is applied to the second pixel electrode 128, and a common voltage is applied to the common electrode, other four domains are defined according to the protrusions 119, 129.
Referring also to FIG. 20, because the voltages of the first pixel electrode 127 is different from the voltage of the second pixel electrode 128 in each frame, a tilt angle θ1 of the liquid crystal molecules 131 in the first sub-pixel region 101 is different from a tilt angle θ2 of the liquid crystal molecules 131 in the second sub-pixel region 102. Thus, a total of eight domains are defined in each pixel region 10.
However, each pixel region 10 needs a first data line 123 and a second data line 124 for the LCD device 100 to be able to achieve 8-domain vertical alignment. The layout of the first data line 123 and the second data line 124 is complicated, resulting in a reduction of an aperture ratio of the LCD 100. Furthermore, the cost of the LCD 100 is correspondingly increased.
It is desired to provide an improved LCD which can overcome the above-described deficiencies.